1. Field of the Invention
The present invention relates to an image forming apparatus, an image forming system, and a post processing method.
2. Discussion of the Background
An image forming system including an image forming apparatus and a post processing apparatus is widely used in offices and the like. The image forming apparatus prints a recording medium based on digital image data acquired by reading a document or through a network. The post processing apparatus receives and executes post processing on the printed recording medium. The post processing herein refers to various types of processing including stapling processing of stapling recording media and punching processing of punching a hole for filing in the recording media.
In recent years, there is a growing demand for use of this kind of image forming system for small business purposes including SOHO (Small Office/Home Office) and private businesses. Additionally, many small businesses with small offices have very limited space, and this has created a demand for minimal space dedicated to the image forming system.
Japanese Unexamined Patent Application Publication No. 2004-155566 discloses an image forming system in which an image reader configured to read an image on a document is disposed above an image forming unit, and a post processing apparatus is embedded in a discharged sheet space between the image reader and the image forming unit so as to acquire space-saving. As in general image forming apparatuses, in the image forming apparatus described in Japanese Unexamined Patent Application Publication No. 2004-155566, the maximum sheet feed width of the image forming unit matches the shorter side length of a maximum size recording medium of a maximum size to be accommodated in a feeder, and the maximum size recording medium is fed and discharged to and from the image forming unit with the shorter side first. The post processing apparatus described in Japanese Unexamined Patent Application Publication No. 2004-155566 simply executes post processing only on a side of the printed recording media orthogonal to a conveyance direction (side along the sheet feed width direction). Accordingly the post processing on the maximum size recording medium is executed only on the shorter side.
In other words, it is not possible to execute the post processing on a longer side of the maximum size recording medium with the configuration described in Japanese Unexamined Patent Application Publication No. 2004-155566. In this case, in order to execute the post processing on the longer side of the maximum size recording medium, it is necessary to replace the above-described post processing apparatus with a post processing apparatus which is capable of executing the post processing on a side of the recording medium along the conveyance direction, or a post processing apparatus which is capable of executing the post processing on both of the sides of the recording medium, the sides being respectively orthogonal and parallel to the conveyance direction, for example. In the former case, two post processing apparatuses are required, which results in cost increase. In the latter case, the structure of the post processing apparatus becomes complicated, thereby increasing the size of the post processing apparatus as well as leading to cost increase. Accordingly, the image forming system is made to be a system against the original intention of acquiring space-saving.